One of my rays has fungus on her tail. I noticed it about a week ago and added salt raised the temp to 84. Its gotten a little better but wont fully go away. I woke up this morning and noticed a little spot on my other female as well. Suggestions? I've been doing a ton of water changes, like 50% every other day. The nitrate comes out of my tap at 15ppm, so I never have perfect nitrates. Does that have something to do with it? Any advice would be appreciated.